JP5899032B2 - Optical film, method for manufacturing optical film, polarizing plate, stereoscopic image display device, and stereoscopic image display system - Google Patents

Description

  The present invention relates to an optical film, an optical film manufacturing method, a polarizing plate, a stereoscopic image display device, and a stereoscopic image display system.

  A stereoscopic (3D) image display device that displays a stereoscopic image requires an optical member for converting the right-eye image and the left-eye image into, for example, circularly polarized images in opposite directions. For example, such an optical member uses a patterned optically anisotropic layer in which regions having different slow axes and retardations are regularly arranged in a plane, and supports the patterned optically anisotropic layer. As a body, a movement using a pattern retardation film using a support made of a film (support film) from the viewpoints of continuous productivity, handleability, thinning, weight reduction, and economy is spreading.

  A stereoscopic image display device using a support film includes, for example, pixels for left and right eye images present in a display panel unit such as a liquid crystal panel, and phase difference regions for left and right eye images of a pattern optical anisotropic layer, respectively. It is necessary to paste in correspondence.

  Cellulose acylate is preferably used as a material suitable for the support film, but the film-formed cellulose acylate film may undergo dimensional changes due to changes in temperature and humidity. For this reason, even if the pixels for the left and right eye images existing in the display panel unit such as a liquid crystal panel and the phase difference regions for the left and right eye images of the pattern optical anisotropic layer are bonded in correspondence with each other, the cellulose Due to the dimensional change of the rate film, a positional deviation between the pattern optical anisotropic layer pattern and the pixel of the display panel occurs. If this positional deviation occurs in a direction perpendicular to the pattern major axis direction of the patterned optically anisotropic layer, there is a problem that crosstalk occurs.

  For this reason, for example, in Patent Document 1, it is proposed to suppress a dimensional change in a direction orthogonal to the pattern major axis direction when a patterned optical anisotropic layer is disposed on a polymer serving as a support. As one of means for achieving the above, a method has been proposed in which a polymer film is stretched in one direction to reduce a dimensional change in the stretching direction.

JP 2011-191756 A

However, as a result of further studies by the present inventors, it has been found that when cellulose acylate is used for the support, improvement in light-resistant adhesion with an adjacent layer may be further required.
In addition, the improvement of the light-resistant adhesion is particularly effective when the support is stretched in order to improve the dimensional change, and in the case of a patterned retardation film in which the number of times of UV irradiation is larger than usual for the convenience of producing an optically anisotropic layer. I found out that

In order to solve the above-mentioned problems, the present inventors diligently studied. As a result, it was found that by adding a hindered amine compound to cellulose acylate, the light-resistant adhesion between the cellulose acylate film and the adjacent functional layer can be improved. The invention has been completed.
Inclusion of a hindered amine compound in the cellulose acylate film is described in JP-A-2009-167416 and JP-A-2006-104374. It can be said that it has been heretofore unknown that the adhesion between the support and the functional layer can be improved by containing a hindered amine compound, for the purpose such as a stabilizer.

  The present invention has been made to solve the above-described problems, and an optical film having improved light-resistant adhesion between a functional layer and a support film, a production method thereof, a polarizing plate having the same, a stereoscopic image display device, and a stereoscopic It is an object to provide an image display system.

The means for solving the problem is the means [1] below, preferably the means [2] to [13] below.
[1] a support containing cellulose acylate;
On the support, a patterned optical anisotropic layer in which at least one of the in-plane slow axis direction or the phase difference is different from each other in the first retardation region and the second retardation region arranged in a predetermined pattern;
An optical film having
The hindered amine compound is contained in the support, and the hindered amine compound is contained in an amount of 0.001% by mass or more based on the cellulose acylate.
An optical film comprising a functional layer on a surface opposite to the surface having the patterned optically anisotropic layer of the support.
[2] The optical film of [1], wherein the sound velocity in the direction orthogonal to the transport direction of the support is 1.8 to 3.0 km / s.
[3] The optical film according to [1], wherein the sound velocity in the direction orthogonal to the transport direction of the support is 2.1 to 2.7 km / s.
[4] The optical film according to any one of [1] to [3], wherein the support is stretched in a direction orthogonal to the transport direction.
[5] The in-plane retardation Re (550) of the support at a wavelength of 550 nm is −5 to 5 nm, and the retardation Rth (550) in the thickness direction at a wavelength of 550 nm is −100 to 100 nm. Optical film in any one of-[4].
[6] The optical film according to any one of [1] to [5], wherein the functional layer is a hard coat layer.
[7] A step of stretching a film containing at least cellulose acylate and a hindered amine compound;
Disposing a functional layer on the film;
Arranging a pattern optical anisotropic layer on the surface of the film opposite to the surface on which the functional layer is disposed, in this order,
The method for producing an optical film, wherein the hindered amine compound is contained in an amount of 0.001% by mass or more based on the cellulose acylate.
[8] The method for producing an optical film according to [7], wherein the step of stretching the film is a step of stretching in a direction orthogonal to the transport direction.
[9] The step of disposing the patterned optically anisotropic layer on the film includes disposing the patterned optically anisotropic layer via an alignment film,
The method for producing an optical film according to [7] or [8], comprising a step of irradiating at least one of the alignment film or the patterned optically anisotropic layer with ultraviolet rays.
[10] A polarizing plate using the optical film of any one of [1] to [6].
[11] A display panel driven based on an image signal;
The stereoscopic image display apparatus which has at least the optical film in any one of [1]-[6] arrange | positioned at the visual recognition side of the said display panel.
[12] A stereoscopic image display system including at least the stereoscopic image display device according to [11] and a polarizing plate disposed on a viewing side of the stereoscopic image display device, and allowing a stereoscopic image to be visually recognized through the polarizing plate.
[13] The hindered amine compound at a position where the concentration C1 of the hindered amine compound at a position 3 μm in the thickness direction from the surface of one surface of the support is half the film thickness of the optical film in the thickness direction from the surface of the support. The optical film of any one of [1] to [6], which is higher than the density C2.

  ADVANTAGE OF THE INVENTION According to this invention, the optical film which improved the light-resistant adhesion of a functional layer and a support body film, its manufacturing method, a polarizing plate which has it, a three-dimensional image display apparatus, and a three-dimensional image display system can be provided.

It is a top view of an example of the optical film of the present invention. It is an upper surface schematic diagram of an example of the pattern optical anisotropic layer concerning this invention. It is an upper surface schematic diagram of an example of the alignment film concerning this invention. It is the schematic which shows an example when casting the cellulose acylate film of a 3 layer structure by simultaneous co-casting using a co-casting die.

  Hereinafter, the present invention will be described in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. First, terms used in this specification will be described.

Re (λ) and Rth (λ) represent in-plane retardation at wavelength λ and retardation in the thickness direction, respectively. Re (λ) is measured with KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of λ nm incident in the normal direction of the film. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like. When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method. This measuring method is also partially used for measuring the average tilt angle on the alignment film side of the discotic liquid crystal molecules in the optically anisotropic layer, which will be described later, and the average tilt angle on the opposite side.
Rth (λ) is the film surface when Re (λ) is used and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) (if there is no slow axis) Measurement is performed at a total of 6 points by injecting light of wavelength λ nm from each inclined direction in steps of 10 degrees from the normal direction to 50 ° on one side with respect to the film normal direction (with any rotation direction as the rotation axis). Then, KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value. In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative. The retardation value is measured from two inclined directions with the slow axis as the tilt axis (rotation axis) (if there is no slow axis, the arbitrary direction in the film plane is the rotation axis). Rth can also be calculated from the following formula (A) and formula (B) based on the value, the assumed value of the average refractive index, and the input film thickness value.

なお、上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値を表す。また、式（Ａ）におけるｎｘは、面内における遅相軸方向の屈折率を表し、ｎｙは、面内においてｎｘに直交する方向の屈折率を表し、ｎｚは、ｎｘ及びｎｙに直交する方向の屈折率を表す。ｄは膜厚である。
Ｒｔｈ＝（（ｎｘ＋ｎｙ）／２−ｎｚ）×ｄ・・・・・・・・・・・式（Ｂ）

Note that Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. In the formula (A), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction orthogonal to nx in the plane, and nz is the direction orthogonal to nx and ny. Represents the refractive index. d is the film thickness.
Rth = ((nx + ny) / 2−nz) × d (Equation (B)

  When the film to be measured is a film that cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film without a so-called optical axis, Rth (λ) is calculated by the following method. Rth (λ) is from −50 ° to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotary axis). Measured at 11 points by making light of wavelength λ nm incident in 10 ° steps up to + 50 °, and based on the measured retardation value, average refractive index assumption value and input film thickness value. KOBRA 21ADH or WR is calculated. In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. If the average refractive index is not known, it can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

In the present specification, “visible light” means 380 nm to 780 nm. Moreover, in this specification, when there is no special mention about a measurement wavelength, a measurement wavelength is 550 nm.
Further, in the present specification, regarding the angle (for example, an angle such as “90 °”) and the relationship (for example, “orthogonal”, “parallel”, “crossing at 45 °”, etc.), the technical field to which the present invention belongs. The range of allowable error is included. For example, it means that the angle is within the range of strict angle ± 10 °, and the error from the strict angle is preferably 5 ° or less, and more preferably 3 ° or less.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the relative relationships of the thicknesses of the layers in the drawings do not reflect actual relative relationships. In the drawings, the same members are denoted by the same reference numerals, and detailed description may be omitted.

  The optical film of the present invention is a pattern retardation film (FPR), and includes a cellulose acylate, a support containing 0.001% by mass or more of a hindered amine compound with respect to the cellulose acylate, And a patterned optical anisotropic layer in which at least one of the in-plane slow axis direction and the phase difference is different from each other, and a pattern optical anisotropic layer in which the second retardation region is arranged in a predetermined pattern, and the pattern optics of the support A functional layer is provided on a surface opposite to the surface having the anisotropic layer.

In the present invention, a stretched film is preferably used as the support. When a stretched film is used, the dimensional change in the stretching direction can be improved, and the positional deviation between the pattern optically anisotropic layer pattern and the display panel pixel can be reduced. Moreover, the optical film of this invention is provided with functional layers, such as a hard-coat layer, in the surface on the opposite side to the surface which has an optically anisotropic layer of a support body.
However, when a stretched film is used, the adhesiveness between the functional layer and the support may be deteriorated due to the deterioration of brittleness. Furthermore, if an optically anisotropic layer is provided after the functional layer is provided on the support, the functional layer is damaged at the UV (ultraviolet) light irradiation stage for the formation of the optically anisotropic layer, and light-resistant adhesion is achieved. Sexuality may worsen.
Further, in the formation of the patterned optically anisotropic layer, it is generally formed using an alignment film that has been subjected to alignment treatment by irradiating UV light a plurality of times, but in that case, the light-resistant adhesion may be deteriorated.
In the present invention, this problem is solved by adding a hindered amine compound to cellulose acylate. It has been found that the light-resistant adhesion to the functional layer can be improved by the action of suppressing the photodegradation of the hindered amine compound cellulose acylate. This can be said to be an unexpected effect that has never been known.

  FIG. 1 shows a schematic cross-sectional view of an example of the optical film of the present invention, and FIG. 2 shows a top view thereof. The optical film 10 shown in FIGS. 1 and 2 includes a transparent support film 14, an optically anisotropic layer 12, and a functional layer 16, and the optically anisotropic layer 12 includes first and The second retardation regions 12a and 12b are patterned optically anisotropic layers arranged uniformly and symmetrically. The first and second retardation regions 12a and 12b preferably have in-plane slow axes a and b that are orthogonal to each other.

  The support film 14 contains cellulose acylate and 0.001% by mass or more of a hindered amine compound with respect to the cellulose acylate. Details of the cellulose acylate and the hindered amine compound will be described later.

  The patterned optically anisotropic layer 12 can be formed from one or more curable compositions containing a liquid crystal compound as a main component, and among the liquid crystal compounds, a liquid crystal compound having a polymerizable group is preferable. It is preferably formed from one of the curable compositions. The patterned optically anisotropic layer 12 may have a single layer structure or a laminated structure of two or more layers. The patterned optically anisotropic layer can be formed from one or two types of compositions containing a liquid crystal compound as a main component.

  As shown in FIG. 2, the pattern optical anisotropic layer 12 has an in-plane retardation Re and in-plane retardation axes a and b of the first and second retardation regions 12a and 12b that are orthogonal to each other. A pattern λ / 4 layer that is λ / 4. When the patterned optically anisotropic layer of this aspect is combined with a polarizing film, the light that has passed through each of the first and second retardation regions becomes a circularly polarized state in opposite directions, and the right and left eye circles respectively. A polarized image is formed.

  The optical film 10 of the present invention is useful as a member of a 3D image display device, particularly a passive 3D image display device. In this aspect, the polarized image that has passed through each of the first and second phase difference regions is recognized as an image for the right eye or the left eye through polarized glasses or the like. Therefore, it is preferable that the first and second phase difference regions have the same shape so that the left and right images do not become non-uniform, and that the respective arrangements are preferably uniform and symmetrical.

  In the present invention, the patterned optically anisotropic layer is not limited to the embodiment shown in FIG. A display pixel region in which one in-plane retardation of the first and second retardation regions is λ / 4 and the other in-plane retardation is 3λ / 4 can be used. Further, a retardation region in which one in-plane retardation of the first and second retardation regions 12a and 12b is λ / 2 and the other in-plane retardation is 0 may be used.

  The in-plane slow axis of each pattern in the first and second retardation regions can be adjusted in different directions, for example, directions orthogonal to each other by using a pattern alignment film or the like. As the pattern alignment film, a photo-alignment film that can form a patterning alignment film by mask exposure, a rubbing alignment film that can form a patterning alignment film by mask rubbing, and a different alignment film (for example, orthogonal or parallel to rubbing) Any material that is patterned by printing or the like can be used.

The optical film of the present invention has the functional layer 16 on the surface opposite to the surface having the patterned optical anisotropic layer. An example of the functional layer 16 is a hard coat layer, an antireflection layer, a low reflection layer, an antiglare layer, a forward scattering layer, a primer layer, an antistatic layer, and an undercoat layer. Two or more functional layers may be arranged. Details of the functional layer will be described later.
In addition, an alignment film may be provided between the support and the patterned optically anisotropic layer.

  The present invention also relates to a method for producing an optical film. The method for producing an optical film of the present invention includes a step of dissolving a cellulose ester and 0.001% by mass or more of a hindered amine compound with respect to the cellulose acylate in an organic solvent, preparing a dope, and forming a film. The step of stretching the film (support), the functional layer is disposed on the support, the functional layer is disposed, and the pattern optical anisotropic layer is opposite to the surface of the support on which the functional layer is disposed. And a step of applying the patterned optically anisotropic layer on the support.

  0.001% by mass or more of a hindered amine compound is dissolved in an organic solvent with respect to the cellulose ester and the cellulose acylate, and a dope is prepared to form a film (form a film). As a method for forming a film by preparing a dope, casting, co-casting, etc. can be used. By co-casting, the air side surface layer / core layer / support side surface layer can be individually designed. It is preferable to form.

  After forming the film, the film is stretched. The direction of stretching is not particularly limited, but it is preferable to stretch in the direction (TD direction) perpendicular to the transport direction. By stretching, the sound velocity in the direction orthogonal to the film transport direction is preferably 1.8 to 3.0 km / s. Specifically, the stretching ratio is 5% or more and 200% or less. it can.

  After stretching the film, the functional layer is disposed by a method such as coating, and the optically anisotropic layer is disposed by a method such as coating on the surface opposite to the surface on which the functional layer is formed. When arranging an optically anisotropic layer, a patterned alignment film is formed, an optically anisotropic layer is disposed on the alignment film, and the optically anisotropic layer is cured by UV irradiation to form a patterned optically anisotropic layer To form. When the pattern alignment film and the optically anisotropic layer are formed, 0 to 2 times of UV irradiation may be performed, so that the light-resistant adhesion between the functional layer and the support may be deteriorated. Since the hindered amine compound is contained in the support, the light-resistant adhesion can be improved.

  The present invention also relates to a polarizing plate. The polarizing plate of the present invention has at least a polarizing film and the optical film of the present invention.

In the polarizing plate of this invention, a polarizing film is arrange | positioned at the surface side of the pattern optical anisotropic layer of an optical film. It is preferable that no other layer is disposed between the patterned optically anisotropic layer and the polarizing film, or only an optically isotropic layer (for example, an adhesive layer) is disposed. .
In addition, the present invention is usually used via a pressure-sensitive adhesive or the like so that the protective film and the patterned optically anisotropic layer are adjacent to each other on a polarizing plate having a protective film bonded to the surface of the polarizing film. A form in which the optical film is arranged is also preferable.

  In the polarizing plate of the present invention, as shown in an example in FIG. 3, the in-plane slow axes a and b of the first and second retardation regions 12a and 12b are set to ± 45 ° with the transmission axis p of the polarizing film, respectively. Arrange. In the present specification, it is not strictly required to be ± 45 °, and any one of the first and second retardation regions 12a and 12b is preferably 40 to 50 °, and the other is -50 to -40 °. With this configuration, it is possible to separate right-eye and left-eye circularly polarized images.

  In the present invention, a general linear polarizing film can be used as the polarizing film. The polarizing film may be a stretched film or a layer formed by coating. Examples of the former include a film obtained by dyeing a stretched film of polyvinyl alcohol with iodine or a dichroic dye. Examples of the latter include a layer in which a composition containing a dichroic liquid crystalline dye is applied and fixed in a predetermined alignment state.

  The present invention also relates to a stereoscopic image display device having at least the optical film of the present invention and a display panel driven based on an image signal. An optical film is arrange | positioned at the visual recognition side surface of a display panel, and isolate | separates into the polarization image (for example, circularly polarized image) for right eyes and left eyes. An observer observes these polarized images through a polarizing plate such as polarized glasses (for example, circular polarized glasses) and recognizes them as a stereoscopic image.

  As shown in FIG. 3, the optical film of the present invention is disposed on the viewing side surface of the display panel together with the polarizing film. However, when the display panel has the polarizing film on the viewing side, there is no polarizing film. Good.

  In the present invention, there is no limitation on the display panel. For example, it may be a liquid crystal panel including a liquid crystal layer, an organic EL display panel including an organic EL layer, or a plasma display panel. For any aspect, various possible configurations can be employed. Moreover, although a liquid crystal panel etc. have the polarizing film for an image display on the visual recognition side surface, you may achieve the said function by a combination with the said polarizing film as above mentioned.

  An example of the display panel is a transmissive mode liquid crystal panel, which includes a pair of polarizing films and a liquid crystal cell therebetween. A retardation film for viewing angle compensation is usually disposed between each of the polarizing films and the liquid crystal cell. There is no restriction | limiting in particular about the structure of a liquid crystal cell, The liquid crystal cell of a general structure is employable. The liquid crystal cell includes, for example, a pair of substrates disposed opposite to each other and a liquid crystal layer sandwiched between the pair of substrates, and may include a color filter layer as necessary. The driving mode of the liquid crystal cell is not particularly limited, and is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically compensated bend cell (OCB). Various modes such as can be used.

  The present invention also relates to a stereoscopic image display system including at least the stereoscopic image display device of the present invention and a polarizing plate disposed on the viewing side of the stereoscopic image display device, and allowing a stereoscopic image to be visually recognized through the polarizing plate. An example of the polarizing plate disposed outside the viewing side of the stereoscopic image display device is polarized glasses worn by an observer. The observer observes the right-eye and left-eye polarized images displayed by the stereoscopic image display device through circularly polarized light or linearly polarized glasses and recognizes them as a stereoscopic image.

  Hereinafter, various members used in the optical film of the present invention will be described in detail.

(Support film)
The support film contains cellulose acylate and 0.001% by mass or more of a hindered amine compound with respect to the cellulose acylate.

Cellulose acylate:
Examples of cellulose as a raw material of cellulose acylate used for the support film (hereinafter also referred to as cellulose acylate film) include cotton linter and wood pulp (hardwood pulp, conifer pulp), and are obtained from any raw material cellulose. Cellulose acylate can also be used, and in some cases, it may be used as a mixture. Detailed descriptions of these raw material celluloses can be found, for example, by Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Institute of Invention and Technology Publication No. 2001. The cellulose described in No.-1745 (pages 7 to 8) can be used.

  The cellulose acylate used in the cellulose acylate film may have only one type of acyl group, or two or more types of acyl groups may be used. The cellulose acylate used for the cellulose acylate film preferably has an acyl group having 2 to 4 carbon atoms as a substituent. Examples of the acyl group having 2 to 4 carbon atoms include an acetyl group, a propionyl group, and a butanoyl group, and an acetyl group is preferable. When two or more kinds of acyl groups are used, it is preferable that one of them is an acetyl group. These cellulose acylates can produce a solution having a preferable solubility, and in particular, a non-chlorine organic solvent can be used to produce a good solution. Furthermore, it becomes possible to produce a solution having a low viscosity and good filterability.

  The cellulose acylate preferably used in the present invention will be described in detail. Glucose units having β-1,4 bonds constituting cellulose have free hydroxyl groups at the 2nd, 3rd and 6th positions. Cellulose acylate is a polymer obtained by acylating part or all of these hydroxyl groups with an acyl group. The degree of acyl substitution means the sum of the ratios of acylation of the hydroxyl groups of cellulose located at the 2-position, 3-position and 6-position (100% acylation at each position is substitution degree 1).

  The total acyl substitution degree of the cellulose acylate is preferably 2.0 to 2.97, more preferably 2.5 or more and less than 2.97, and preferably 2.70 to 2.95. Particularly preferred.

  The acyl group having 2 or more carbon atoms of the cellulose acylate may be an aliphatic group or an allyl group, and is not particularly limited. Cellulose acylates substituted with these acyl groups are, for example, cellulose alkyl carbonyl esters, alkenyl carbonyl esters, aromatic carbonyl esters, aromatic alkyl carbonyl esters, and the like, and each may further have a substituted group. Good. Preferred examples of the acyl group include acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, Examples thereof include an isobutanoyl group, a tert-butanoyl group, a cyclohexanecarbonyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, and a cinnamoyl group. Among these, an acetyl group, a propionyl group, a butanoyl group, a dodecanoyl group, an octadecanoyl group, a tert-butanoyl group, an oleoyl group, a benzoyl group, a naphthylcarbonyl group, a cinnamoyl group, and the like are more preferable, and an acetyl group is particularly preferable. A propionyl group and a butanoyl group (when the acyl group has 2 to 4 carbon atoms), more preferably an acetyl group (when the cellulose acylate is cellulose acetate).

  In the acylation of cellulose, when an acid anhydride or acid chloride is used as an acylating agent, an organic acid such as acetic acid or methylene chloride is used as an organic solvent as a reaction solvent.

As the catalyst, when the acylating agent is an acid anhydride, a protic catalyst such as sulfuric acid is preferably used, and when the acylating agent is an acid chloride (for example, CH ₃ CH ₂ COCl), Basic compounds are used.

  The most common industrial synthesis method of cellulose mixed fatty acid ester is to use cellulose corresponding to fatty acid corresponding to acetyl group and other acyl groups (acetic acid, propionic acid, valeric acid, etc.) or their acid anhydrides. This is a method of acylating with a mixed organic acid component.

  The cellulose acylate can be synthesized, for example, by the method described in JP-A-10-45804.

  The cellulose acylate film preferably contains 5 to 99% by mass of cellulose acylate as a resin from the viewpoint of moisture permeability, more preferably 20 to 99% by mass, and particularly preferably 50 to 95% by mass.

Hindered amine compounds:
A hindered amine compound (hereinafter also referred to as “HALS”) functions as an antioxidant and has a structure having a bulky organic group (for example, a bulky branched alkyl group) in the vicinity of the N atom. This is a known compound and is described, for example, in US Pat. No. 4,619,956, columns 5-11 and US Pat. No. 4,839,405, columns 3-5. As such, 2,2,6,6-tetraalkylpiperidine compounds, or their acid addition salts or complexes thereof with metal compounds are included. Such compounds include those of the following general formula (2).

In the above formula, R1 and R2 are a hydrogen atom or a substituent.
Specific examples of hindered amines include 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-benzyl-4-hydroxy -2,2,6,6-tetramethylpiperidine, 1- (4-tert-butyl-2-butenyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2, 2,6,6-tetramethylpiperidine, 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6-pentamethyl Piperidine, 1,2,2,6,6-pentamethylpiperidin-4-yl-β (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, 1-benzyl- , 2,6,6-tetramethyl-4-piperidinylmaleate, (di-2,2,6,6-tetramethylpiperidin-4-yl) -adipate, (di-2,2, 6,6-tetramethylpiperidin-4-yl) -sebacate, (di-1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -sebacate, (di-1-allyl) -2,2,6,6-tetramethyl-piperidin-4-yl) -phthalate, 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl-acetate, trimellitic acid-tri- (2 , 2,6,6-tetramethylpiperidin-4-yl) ester, 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine, dibutyl-malonic acid-di- (1,2, 2 , 6,6-pentamethyl-piperidin-4-yl) -ester, dibenzyl-malonic acid-di- (1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -ester, Dimethyl-bis- (2,2,6,6-tetramethylpiperidin-4-oxy) -silane, tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphite , Tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphate, N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl ) -Hexamethylene-1,6-diamine, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6) , 6 Pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, N, N′-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -hexamethylene-1,6 -Diacetamide, 1-acetyl-4- (N-cyclohexylacetamido) -2,2,6,6-tetramethyl-piperidine, 4-benzylamino-2,2,6,6-tetramethylpiperidine, N, N '-Bis- (2,2,6,6-tetramethylpiperidin-4-yl) -N, N'-dibutyl-adipamide, N, N'-bis- (2,2,6,6-tetramethylpiperidine -4-yl) -N, N'-dicyclohexyl- (2-hydroxypropylene), N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -p-xylylene-diam 4- (bis-2-hydroxyethyl) -amino-1,2,2,6,6-pentamethylpiperidine, 4-methacrylamide-1,2,2,6,6-pentamethylpiperidine, α-cyano -Β-methyl-β- [N- (2,2,6,6-tetramethylpiperidin-4-yl)]-amino-acrylic acid methyl ester.

  Furthermore, N, N ′, N ″, N ′ ″-tetrakis- [4,6-bis- [butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino]- Triazin-2-yl] -4,7-diazadecane-1,10-diamine, dibutylamine and 1,3,5-triazine N, N'-bis (2,2,6,6-tetramethyl-4- Piperidyl) -1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (BAMIS CHIMASSORB 2020FDL), dibutylamine and 1,3, Polycondensation product of 5-triazine and N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1,1,3,3-tetramethylbutyl) amino -1,3,5 -Triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (CHIMASSORB 944FDL manufactured by BASF), 1,6-hexanediamine-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) and morpholine-2,4,6-trichloro-1 , 3,5-triazine polycondensate, poly [(6-morpholino-s-triazine-2,4-diyl) [(2,2,6,6, -tetramethyl-4-piperidyl) imino]- High molecular weight HALS in which a plurality of piperidine rings are bonded via a triazine skeleton, such as hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]]; dimethyl succinate and 4 -Polymer with hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4- Piperidine rings such as mixed esterified products of piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane are ester-bonded. Examples include, but are not limited to, a high molecular weight HALS bonded via a. Among these, polycondensates of dibutylamine, 1,3,5-triazine and N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1, 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2 , 2,6,6-tetramethyl-4-piperidyl) imino}], a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, etc. Those having a molecular weight (Mn) of 2,000 to 5,000 are preferred.

  Examples of preferred hindered amine compounds include the following HALS-1 and HALS-2. In the following HALS-1, n represents the number of repeating units.

Among the above specific examples, CHIMASORB 2020FDL (CAS-No. 192268-64-7) manufactured by BASF (former Ciba Specialty Chemicals Co., Ltd.), C
HIMASORB 944FDL (CAS-No. 71878-19-8), and TI
NUVIN 770DF (CAS-No. 52829-07-9), Siasorb UV-3346 (CAS-No. 82541-48-7) manufactured by Sun Chemical Co., Ltd., and Siasorb UV-3529 (CAS-No. 1930998-40-7) ) Is preferred because it is commercially available and has excellent availability.

  In addition, although the said hindered amine type compound may be obtained commercially as mentioned above, you may use what was manufactured by the synthesis | combination. There is no restriction | limiting in particular as a synthesis method of the said hindered amine type compound, It can synthesize | combine by the method in a normal organic synthesis. Moreover, as a production | generation method, the method using distillation, recrystallization, reprecipitation, and a filter agent and adsorption agent can be used suitably. In addition, the commercially available products that are available at low cost are not limited to the hindered amine compounds, but may be mixtures. In the present invention, any of these embodiments may be obtained commercially. It can be used regardless of the composition, melting point, acid value and the like.

The hindered amine compound used in the present invention may be a low molecular weight polymer or a polymer having a repeating unit, but the hindered amine is present in the vicinity of the interface between the active energy ray UV curable resin layer and the cellulose acylate film. In order to make the system compound unevenly distributed, a high molecular weight is preferable. On the other hand, if the molecular weight is too high, the compatibility with cellulose acylate is insufficient, and the haze of the film becomes high.
The hindered amine compound preferably has a molecular weight of 300 to 100,000, more preferably 700 to 50,000, and particularly preferably 2,000 to 30,000.

The hindered amine compound used in the present invention is preferably dissolved in a ketone solvent in an amount of 0.01% by mass or more. By using such a hindered amine compound, the hindered amine compound added to the cellulose acylate film when producing the optical film of the present invention is preferably a ketone type used when forming a functional layer described later. It is preferable that the hindered amine-based compound is contained in the functional layer after being dissolved in a solvent.
Examples of the ketone solvent include MiBK (methyl isobutyl ketone), MEK (methyl ethyl ketone), and the like.

The cellulose acylate film contains 0.001% by mass or more of a hindered amine compound, preferably 0.001 to 15% by mass or less, and 0.001 to 10% by mass with respect to cellulose acylate. It is more preferable to contain 0.05 to 5% by mass.
Adhesiveness between a functional layer and the said support body film can fully be ensured because content of a hindered amine type compound shall be 0.001 mass% or more with respect to a cellulose acylate film. Although there is no restriction | limiting in particular about an upper limit, By making it 15 mass% or less, it becomes difficult to produce the bleed-out of a hindered amine type compound.

Other additives:
In the cellulose acylate film, additives such as plasticizers such as phthalate esters and phosphate esters; ultraviolet absorbers; antioxidants; matting agents may be added.

(Plasticizer)
The film of the present invention contains at least one plasticizer. The film of the present invention preferably contains a plasticizer in an amount of 3% by mass to 30% by mass, more preferably 5% by mass to 25% by mass, based on the total mass of the cellulose acylate. It is particularly preferable to contain 5 to 20% by mass. When the plasticizer content is less than 3% by mass with respect to the cellulose acylate film, the film-forming property in the solution casting method or the like may be inferior. On the other hand, when the content exceeds 30% by mass, the problem of bleeding out, etc. Occurs.

As the plasticizer used in the present invention, many compounds known as a plasticizer for cellulose acylate can be used.
Examples of plasticizers that can be used include phosphate esters. Examples of phosphate esters include triphenyl phosphate (TPP), biphenyl diphenyl phosphate (BDP), and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters.

  Examples of the plasticizer that can be used in the present invention include non-phosphate ester compounds. Non-phosphate ester compounds include carboxylic acid esters. Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred.

Other examples of non-phosphate ester plasticizers include polyhydric alcohols, aliphatic dibasic esters, acetate esters, polyester epoxidized esters, ricinoleate esters, polyolefins, polyethylene glycol compounds Polyhydric alcohol type and polyester type are preferable, and polyester type is more preferable.
As plasticizers for non-phosphate ester compounds, for example, polyester additives include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic diols having an average carbon number of 2.0 or more and 3.0 or less, and monocarboxylic acids. Although it is a polycondensation ester which can be obtained from the mixture containing an acid and both ends were sealed with acetic acid, it is not limited to these.
Moreover, as a plasticizer of a non-phosphate ester compound, a plasticizer containing a benzene ring is preferable from the viewpoint of optical performance and moisture permeability. In the present invention, only a plasticizer containing a benzene ring may be used, or a plasticizer containing a benzene ring and another plasticizer containing no benzene ring may be used in combination.
Examples of plasticizers for non-phosphate compounds include the following phthalic acid esters 1, polyhydric alcohol esters 1 to 4, and citric acid esters 1, but phthalic acid esters, polyhydric alcohol esters, and citric acid. The ester is not limited to these.
Two or more additives of non-phosphate ester compounds may be used in combination.

  When the cellulose acylate film is produced by co-casting, the concentration of the plasticizer at the position of 3 μm in the thickness direction from the one film surface is the concentration A, and the concentration of the plasticizer at the position of 10 μm in the thickness direction from the one film surface. B satisfies the relationship of A <B. From the viewpoint of obtaining high adhesiveness regardless of the type of plasticizer, the concentration A of the plasticizer in the vicinity of the film surface is preferably as low as possible. Specifically, it is preferably 8% by mass or less, and preferably 5% by mass or less. More preferably, it is 1% by mass or less. On the other hand, the concentration A of the plasticizer may be 0 mass, but is preferably 0.1 mass% or more from the viewpoint of film forming properties. Further, from the viewpoint of optical performance and moisture permeability, the concentration B of the plasticizer in the central part in the film thickness direction is preferably 5 to 25% by mass, more preferably more than 5% by mass and 25% by mass or less. Preferably, it is 5-15 mass% or less. The concentration B-concentration A of the plasticizer is preferably 3% by mass or more, and more preferably 5% by mass or more.

(Antioxidant, UV absorber)
As the antioxidant and ultraviolet absorber used in the present invention, many compounds known as cellulose acylate plasticizers can also be used effectively. For example, paragraph [0083] of JP-A-2012-056795 To [0084], paragraphs [0112] to [0113] of JP-A-2006-328277, paragraphs [0082] to [0083] of JP-A-2012-31313, and the like. Absorbents can be preferably used.

(Matting agent)
As the matting agent used in the present invention, many compounds known as cellulose acylate matting agents can be usefully used. For example, paragraphs [0085] to [0086] of JP2012-056795A, The matting agents described in paragraphs [0094] to [0095] of JP 2012-003209 A can be preferably used.

(Layer structure of film)
The cellulose acylate film may be a single layer or a laminate of two or more layers.
When the cellulose acylate film is a laminate of two or more layers, it is preferably a laminate in which at least one skin layer is laminated on at least one surface of the core layer and the core layer. The laminate is more preferably a two-layer structure or a three-layer structure, and preferably a three-layer structure. In the case of a three-layer structure, when the cellulose acylate film of the present invention is produced by solution casting, a layer in contact with the metal support (hereinafter also referred to as a support surface or a skin B layer), the metal support, Preferably has an air interface layer on the opposite side (hereinafter also referred to as an air surface or a skin A layer) and a single core layer sandwiched therebetween. That is, the film of the present invention preferably has a three-layer structure of skin B layer / core layer / skin A layer.
Moreover, when the said cellulose acylate film is a laminated body of two or more layers, it is preferable that the said skin layer contains the said hindered amine type compound. In this embodiment, the hindered amine compound may diffuse into each layer.

The support film (cellulose acylate film) is a hindered amine at a position where the concentration C1 of the hindered amine compound at a depth of 3 μm from the film surface on one side is half the thickness of the cellulose acylate film of the present invention. It is higher than the concentration C2 of the system compound. C1 is preferably as high as possible. Specifically, it is preferably 0.5% by mass or more, and more preferably 1% by mass or more. On the other hand, since the bleed-out may occur when the concentration is too high, the upper limit value is the same as the preferable upper limit value of the HALS concentration as the whole film. The ratio C1 / C2 between C1 and C2 is more preferably 2 or more, and particularly preferably 3 or more.
By setting it as such an aspect, not only the light-resistant adhesiveness of a functional layer but the light-resistant adhesiveness with a pattern optical anisotropic layer can also be improved.

C1 and C2 of the cellulose acylate film were cut obliquely at an angle of 1 ° with respect to the film surface, and the generated film cross section was measured by mapping with a time-of-flight secondary ion mass spectrometer (TOF-SIMS). It can be calculated from the peak intensity ratio of specifically detected fragment ions.
When the ratio C1 / C2 is high, a functional layer is applied and formed on the surface side where the concentration of the hindered amine compound is high, so that the functional layer is not easily peeled off from the cellulose acylate film even when irradiated with light for a long time.

  In the cellulose acylate film, a method for realizing the above-described concentration distribution of the hindered amine compound is not particularly limited. Can be mentioned.

  In the optical film of the present invention, the cellulose acylate film has a core layer and at least one skin layer laminated on at least one surface of the core layer, and at least one of the skin layers has an active function. More preferably, the skin layer adjacent to the layer and adjacent to the functional layer contains the hindered amine compound. By setting it as such a structure, it becomes easier to show the adhesive improvement effect of this invention.

  The cellulose acylate film preferably has a haze of less than 0.20%, more preferably less than 0.15%, and particularly preferably less than 0.10%. By setting the haze to less than 0.2%, the contrast ratio when incorporated in a liquid crystal display device can be improved. In addition, there is an advantage that the transparency of the film becomes higher and it is easier to use as an optical film.

The cellulose acylate film preferably has an average film thickness of 30 to 100 μm, more preferably 30 to 80 μm, and still more preferably 30 to 70 μm. By setting it to 30 μm or more, the handling property when producing a web-like film is improved, which is preferable. Moreover, by setting it as 70 micrometers or less, it is easy to respond to a humidity change and it is easy to maintain an optical characteristic.
Moreover, when the said cellulose acylate film has a laminated structure of three or more layers, it is preferable that the film thickness of the said core layer is 30-70 micrometers, It is more preferable that it is 30-60 micrometers, It is 30-50 micrometers. Is particularly preferred. When the cellulose acylate film of the present invention has a laminate structure of three or more layers, it is more preferable that the film thicknesses of the surface layers (skin A layer and skin B layer) on both sides of the film are both 0.5 to 20 μm. More preferably, it is 5-10 micrometers, and it is especially preferable that it is 0.5-3 micrometers.

  The cellulose acylate film preferably has a film width of 700 to 3000 mm, more preferably 1000 to 2800 mm, and particularly preferably 1400 to 2500 mm.

The in-plane retardation Re (550) at a wavelength of 550 nm of the cellulose acylate film is preferably −5 to 5 nm, more preferably −3 to 3 nm, and particularly preferably −1 to 3 nm.
Further, the retardation Rth (550) in the thickness direction at a wavelength of 550 nm of the cellulose acylate film is preferably from -100 to 100 nm, more preferably from -50 to 50 nm, particularly preferably from 0 to 50 nm.

<Method for producing cellulose acylate film>
Hereafter, the manufacturing method of the cellulose acylate film used for this invention is demonstrated in detail. In this invention, it is preferable to manufacture by the melt film forming method or the solution film forming method, and manufacturing by the solution film forming method is more preferable. Regarding melt film formation, for example, JP-A-2006-348123 can be referred to, and for solution film formation, for example, JP-A-2006-241433 can be referred to.

  The cellulose acylate film is preferably produced by a solvent cast method. About the manufacture example of the cellulose acylate film using a solvent cast method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,492,078, 2,492,977, 2,492,978, 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640731 and 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035 can be referred to. The cellulose acylate film may be subjected to a stretching treatment. With respect to the stretching method and conditions, for example, refer to JP-A-62-115035, JP-A-4-152125, 4-284221, 4-298310, and 11-48271. can do.

(Casting method)
As a solution casting method, a method in which the prepared dope is uniformly extruded from a pressure die onto a metal support, and a method using a doctor blade in which the dope once cast on the metal support is adjusted with a blade is used. Although there is a method using a reverse roll coater that adjusts with a reverse rotating roll, a method using a pressure die is preferred. The pressure die includes a coat hanger type and a T die type, and any of them can be preferably used. In addition to the methods mentioned here, it can be carried out by various known methods for casting a cellulose triacetate solution, and each condition is set in consideration of differences in the boiling point of the solvent used. Thus, the same effects as those described in the respective publications can be obtained.

《Co-casting》
In the formation of the cellulose acylate film, it is preferable to use a laminating casting method such as a co-casting method, a sequential casting method, and a coating method. In particular, the simultaneous co-casting method is preferably used to reduce stable production and production costs. From the viewpoint of
When manufacturing by the co-casting method and the sequential casting method, first, a cellulose acetate solution (dope) for each layer is prepared. In the co-casting method (multi-layer simultaneous casting), a casting dope for each layer (which may be three layers or more) is simultaneously pressed from a separate slit or the like on a casting support (band or drum). This is a casting method in which the dope is extruded from the casting gies to be cast, and each layer is cast at the same time, peeled off from the support at an appropriate time, and dried to form a film.
FIG. 4 is a sectional view showing a state in which three layers of the skin layer (surface layer) dope 1 and the core layer dope 2 are simultaneously extruded and cast on the casting support 4 using the co-casting giesser 3. .

  In the sequential casting method, the casting dope for the first layer is first extruded from the casting giusa on the casting support, cast, and dried on the second layer without drying or drying. Extrude the casting dope for casting from the casting gieser, cast the dope sequentially to the third layer or more, if necessary, peel it off from the support at an appropriate time, and dry it. This is a casting method for forming a film. In general, the core layer film is formed into a film by a solution casting method to prepare a coating solution to be applied to the skin layer. In this method, a coating film is applied and dried to form a film having a laminated structure.

The endlessly running metal support used to manufacture the cellulose acylate film includes a drum whose surface is mirror-finished by chrome plating and a stainless steel belt (which may be called a band) which is mirror-finished by surface polishing. Good) is used. One or more pressure dies may be installed above the metal support. Preferably 1 or 2 groups. When two or more are installed, the amount of dope to be cast may be divided into various ratios for each die, or the dope may be fed to the dies from each of a plurality of precision quantitative gear pumps. The temperature of the dope (resin solution) used for casting is preferably −10 to 55 ° C., more preferably 25 to 50 ° C. In that case, all solution temperatures in the process may be the same or different at different points in the process. If they are different, the temperature may be a desired temperature just before casting.
Moreover, there is no restriction | limiting in particular about the material of the said metal support body, However, It is more preferable that it is a product made from SUS (for example, SUS316).

(Extension process)
The method for producing a cellulose acylate film preferably includes a step of stretching the formed film. The stretching direction of the cellulose acylate film is preferably either the film transport direction or the direction orthogonal to the transport direction (width direction (TD direction)), but the direction orthogonal to the film transport direction is a viewpoint of reducing crosstalk. Is particularly preferred.

  Methods for stretching in the width direction are described in, for example, JP-A-62-115035, JP-A-4-152125, JP-A-2842211, JP-A-298310, and JP-A-11-48271. Yes. In the case of stretching in the longitudinal direction, for example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed. In the case of stretching in the width direction, the film can also be stretched by conveying while holding the width of the film with a tenter and gradually widening the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine).

  The stretch ratio of the cellulose acylate film is preferably from 0% to 100%, more preferably from 0% to 40%, particularly preferably from 5% to 30%.

  The sound velocity in the direction orthogonal to the conveyance direction of the cellulose acylate film is preferably 1.8 to 3.0 km / s, more preferably 2.1 to 2.7 km / s, and 2.2 to Particularly preferred is 2.5 km / s. Crosstalk is reduced because the rate of change in humidity of the cellulose acylate film is reduced by setting the speed of sound to 1.8 to 3.0 km / s.

  The drying of the dope on the metal support, which is related to the production of the cellulose acylate film, is generally performed by supplying hot air from the surface side of the metal support (drum or belt), that is, from the surface of the web on the metal support. Contact method, a method of applying hot air from the back surface of the drum or belt, a temperature-controlled liquid is brought into contact with the back surface opposite to the belt or drum dope casting surface, and the drum or belt is heated by heat transfer to increase the surface temperature. Although there is a back surface liquid heat transfer method to be controlled, the back surface liquid heat transfer method is preferable. The surface temperature of the metal support before casting may be any number as long as it is not higher than the boiling point of the solvent used for the dope. However, in order to promote drying and to lose fluidity on the metal support, the temperature should be set to 1 to 10 ° C. lower than the boiling point of the lowest boiling solvent. Is preferred. Note that this is not the case when the casting dope is cooled and peeled off without drying.

(Peeling)
The method for producing the cellulose acylate film preferably includes a step of peeling the dope film from the metal support. There is no restriction | limiting in particular about the peeling method in the manufacturing method of the said cellulose acylate film, When a well-known method is used, peelability can be improved.

  The film thickness may be adjusted by adjusting the solid content concentration contained in the dope, the slit gap of the die base, the extrusion pressure from the die, the metal support speed, and the like so as to obtain a desired thickness.

  The length of the cellulose acylate film obtained as described above is preferably wound at 100 to 10000 m per roll, more preferably 500 to 7000 m, and still more preferably 1000 to 6000 m. When winding, it is preferable to give knurling to at least one end, the knurling width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. is there. This may be a single push or a double push.

Pattern optical anisotropic layer:
The patterned optically anisotropic layer in the present invention includes a first retardation region and a second retardation region in which at least one of an in-plane slow axis direction and an in-plane retardation is different from each other, and the first and second positions The phase difference regions are alternately arranged in the plane, and have a boundary portion between the first phase difference region and the second phase difference region. An example is an optically anisotropic layer in which the first and second retardation regions each have Re of about λ / 4 and the in-plane slow axes are orthogonal to each other. There are various methods for forming such a patterned optically anisotropic layer. In the present invention, polymerization is performed in a state in which a rod-like liquid crystal having a polymerizable group is horizontally aligned and a discotic liquid crystal is vertically aligned. It is preferable to form them by fixing them.

  The patterned optically anisotropic layer alone may have Re of about λ / 4. In this case, Re (550) is preferably about λ / 4 ± 30 nm, more preferably 110 to 165 nm, and 120 More preferably, it is -150 nm, and it is especially preferable that it is 125-145 nm. In this specification, the in-plane retardation Re of λ / 4 means a value having a width of about ¼ to ± 30 nm of the wavelength λ unless otherwise specified. λ / 2 refers to a value having a width of about ½ to ± 30 nm of the wavelength λ unless otherwise specified. In many commercially available supports, Rth is a positive value. When the patterned optical anisotropic layer is formed on a support having a positive Rth value, Rth (550) of the patterned optical anisotropic layer is preferably negative, and is from −80 to −50 nm. It is preferable that it is −75 to −60 nm.

In general, liquid crystal compounds can be classified into a rod type and a disk type from the shape. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used, but a rod-like liquid crystal compound or a disk-like liquid crystal compound is preferably used. Two or more kinds of rod-like liquid crystal compounds, two or more kinds of disk-like liquid crystal compounds, or a mixture of a rod-like liquid crystal compound and a disk-like liquid crystal compound may be used. It is more preferable to use a rod-like liquid crystal compound or a disk-like liquid crystal compound having a reactive group, since at least one of the reactive groups in one liquid crystal molecule is at least one because a change in temperature and humidity can be reduced. Is more preferable. The liquid crystal compound may be a mixture of two or more types, and in that case, at least one preferably has two or more reactive groups.
As the rod-like liquid crystal compound, for example, those described in JP-A-11-513019 and JP-A-2007-279688 can be preferably used, and examples of the discotic liquid crystal compound include JP-A-2007-108732 and JP-A-2007-108732. Although what is described in 2010-244038 can be used preferably, it is not limited to these.

  It is also preferable that the liquid crystal compound has two or more reactive groups having different polymerization conditions. In this case, it is possible to produce a retardation layer containing a polymer having an unreacted reactive group by selecting conditions and polymerizing only a part of plural types of reactive groups. The polymerization conditions used may be the wavelength range of ionizing radiation used for polymerization immobilization, or the difference in polymerization mechanism used, but preferably a radical reaction group and a cationic reaction that can be controlled by the type of initiator used. A combination of groups is good. A combination in which the radical reactive group is an acrylic group and / or a methacryl group and the cationic group is a vinyl ether group, an oxetane group and / or an epoxy group is particularly preferable because the reactivity can be easily controlled.

The optically anisotropic layer can be formed by various methods using an alignment film, and the production method is not particularly limited.
The first aspect uses a plurality of actions that affect the alignment control of the liquid crystal, and then eliminates any action by an external stimulus (such as heat treatment) to make the predetermined alignment control action dominant. It is. There exists description in Unexamined-Japanese-Patent No. 2012-008170, The content is taken in into this specification as a reference.

  In the second aspect, a pattern alignment film is used. In this embodiment, pattern alignment films having different alignment control capabilities are formed, and a liquid crystal compound is disposed thereon to align the liquid crystal. The alignment of the liquid crystal is regulated by the respective alignment control ability of the pattern alignment film, thereby achieving different alignment states. By fixing the respective alignment states, the patterns of the first and second retardation regions are formed according to the alignment film pattern. The pattern alignment film can be formed using a printing method, mask rubbing for the rubbing alignment film, mask exposure for the photo alignment film, or the like. Alternatively, the alignment film can be formed uniformly, and an additive that affects the alignment control ability (for example, the onium salt or the like) can be separately printed in a predetermined pattern to form the pattern alignment film. A method using a printing method is preferable in that large-scale equipment is not required and manufacturing is easy. Details of this method are described in JP 2012-032661 A, the contents of which are incorporated herein by reference.

  As another example, a photo acid generator is added to the alignment film. In this example, a photoacid generator is added to the alignment film, and pattern exposure exposes a region where the photoacid generator is decomposed to generate an acidic compound and a region where no acid compound is generated. The photoacid generator remains almost undecomposed in the unirradiated portion, and the interaction between the alignment film material, the liquid crystal, and the alignment control agent added as required dominates the alignment state, and the liquid crystal has its slow axis. Is oriented in a direction perpendicular to the rubbing direction. When the alignment film is irradiated with light and an acidic compound is generated, the interaction is no longer dominant, the rubbing direction of the rubbing alignment film dominates the alignment state, and the liquid crystal has its slow axis parallel to the rubbing direction. Parallel orientation. As the photoacid generator used for the alignment film, a water-soluble compound is preferably used. Examples of photoacid generators that can be used include Prog. Polym. Sci. , 23, 1485 (1998). As the photoacid generator, pyridinium salts, iodonium salts and sulfonium salts are particularly preferably used. Details of this method are described in Japanese Patent Application No. 2010-289360, the contents of which are incorporated herein by reference.

  The thickness of the patterned optically anisotropic layer thus formed is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

Functional layer:
The optical film of the present invention has a functional layer on the surface opposite to the surface having the patterned optically anisotropic layer of the support.
Examples of the functional layer include a forward scattering layer, an antiglare (antiglare) layer, a gas barrier layer, a sliding layer, an antistatic layer, an undercoat layer, a hard coat layer, an antireflection layer, or a protective layer. A hard coat layer is more preferable, and a hard coat layer is particularly preferable.

(Hard coat layer)
The optical film of the present invention is preferably provided on the surface of the cellulose acylate film with a hard coat layer as a functional layer in order to impart mechanical strength such as scratch resistance.
The film thickness of the hard coat layer is preferably 0.2 to 100 μm, more preferably 0.5 to 50 μm, and particularly preferably 1 to 20 μm.
The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

As the material for forming the hard coat layer, a compound containing an ethylenically unsaturated group or a compound containing a ring-opening polymerizable group can be used, and these compounds can be used alone or in combination.
As specific constitutional compositions of the hard coat layer, for example, those described in JP-A Nos. 2002-144913, 2000-9908 and WO0 / 46617 can be preferably used.

(Antireflection layer)
The antireflective layer is either a layer having a reflectivity of about 1.5% only by applying a single layer of a low refractive index material such as a fluorine-based polymer, or a layer having a reflectivity of 1% or less using multilayer interference of a thin film. Can be used. In the present invention, a structure in which a low refractive index layer and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer and a middle refractive index layer) is laminated on a transparent support is preferably used. The In addition, Nitto Technical Report, vol. 38, no. 1, may, 2000, pages 26 to 28, and JP-A No. 2002-301783 can also be preferably used.

(Forward scattering layer)
The forward scattering layer is used to improve the viewing angle characteristics (hue and luminance distribution) in the vertical and horizontal directions when the polarizing plate of the present invention is applied to a liquid crystal display device. In the present invention, a configuration in which fine particles having different refractive indexes are dispersed in a binder is preferable. The construction of JP-A No. 199809, JP-A No. 2002-107512 that defines the haze value as 40% or more can be used. In addition, in order to control the viewing angle characteristics of haze, the polarizing plate of the present invention is also preferably used in combination with “Lumisty” described in Sumitomo Chemical's technical report “Photofunctional Films” on pages 31-39. be able to.

(Anti-glare layer)
The antiglare (antiglare) layer is used to scatter reflected light and prevent reflection. The antiglare function is obtained by forming irregularities on the outermost surface (display side) of the liquid crystal display device. The haze of the film having an antiglare function is preferably 3 to 30%, more preferably 5 to 20%, and particularly preferably 7 to 20%.
The method for forming irregularities on the film surface is, for example, a method of forming irregularities on the film surface by adding fine particles (for example, JP-A No. 2000-271878), relatively large particles (particle size 0.05-2 μm). ) Is added in a small amount (0.1 to 50% by mass) (for example, Japanese Patent Application Laid-Open Nos. 2000-281410, 2000-95893, 2001-100004, and 2001). No. 281407, etc.), a method of physically transferring the uneven shape onto the film surface (for example, as an embossing method, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401) Etc.) can be preferably used.

  There is no restriction | limiting in particular about the formation method of a functional layer, For example, it can form by preparing the coating liquid of a functional layer, and apply | coating on a support body.

LCD cell:
The liquid crystal cell used in the stereoscopic image display device used in the stereoscopic image display system of the present invention is preferably VA mode, OCB mode, IPS mode, or TN mode, but is not limited thereto.
In a TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech.Papers 28) (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) Liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (1998)) and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Moreover, any of PVA (Patterned Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polymer-Sustained Alignment) may be used. Details of these modes are described in JP-A-2006-215326 and JP-T-2008-538819.
In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. The IPS mode displays black when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522 are methods for reducing leakage light at the time of black display in an oblique direction and improving a viewing angle using an optical compensation sheet. No. 11-133408, No. 11-305217, No. 10-307291, and the like.

Polarizing plate for stereoscopic image display system:
In the stereoscopic image display system of the present invention, in order to make the viewer recognize a stereoscopic image called 3D video, the image is recognized through the polarizing plate. One aspect of the polarizing plate is polarized glasses. In the aspect in which the right-polarized and left-eye circularly polarized images are formed by the retardation plate, circularly polarized glasses are used, and in the aspect in which the linearly polarized images are formed, linear glasses are used. Right-eye image light emitted from one of the first and second retardation regions of the optically anisotropic layer is transmitted through the right glasses and shielded by the left glasses, and the first and second positions It is preferable that the image light for the left eye emitted from the other of the phase difference regions is transmitted through the left glasses and shielded by the right glasses.
The polarizing glasses form polarizing glasses by including a retardation functional layer and a linear polarizer. In addition, you may use the other member which has a function equivalent to a linear polarizer.

  A specific configuration of the stereoscopic image display system of the present invention including the polarizing glasses will be described. First, the phase difference plate is formed on a plurality of first lines and a plurality of second lines that are alternately repeated on the video display panel (for example, on odd-numbered lines and even-numbered lines in the horizontal direction if the lines are in the horizontal direction). The first phase difference region and the second phase difference region having different polarization conversion functions are provided on the odd-numbered and even-numbered lines in the vertical direction if the line is in the vertical direction. When circularly polarized light is used for display, the phase difference between the first phase difference region and the second phase difference region is preferably λ / 4, and the first phase difference region and the first phase difference region are In the two phase difference region, it is more preferable that the slow axes are orthogonal.

When using circularly polarized light, the phase difference values of the first phase difference region and the second phase difference region are both set to λ / 4, the right eye image is displayed on the odd lines of the video display panel, and the odd line phase difference is displayed. If the slow axis of the region is in the 45 degree direction, it is preferable to arrange λ / 4 plates on both the right and left glasses of the polarized glasses, and the slow axis of the λ / 4 plate of the right glasses of the polarized glasses is Specifically, it may be fixed at approximately 45 degrees. In the above situation, similarly, the left eye image is displayed on the even line of the video display panel, and if the slow axis of the even line phase difference region is in the direction of 135 degrees, the left eyeglass of the polarizing glasses Specifically, the slow axis may be fixed at approximately 135 degrees.
Furthermore, from the viewpoint of emitting image light as circularly polarized light once in the patterning retardation film and returning the polarization state to the original state by the polarized glasses, the angle of the slow axis fixed by the right glasses in the above example is exactly The closer to 45 degrees in the horizontal direction, the better. Further, it is preferable that the angle of the slow axis fixed by the left spectacles is exactly close to horizontal 135 degrees (or -45 degrees).

For example, when the video display panel is a liquid crystal display panel, the absorption axis direction of the front-side polarizing plate of the liquid crystal display panel is usually a horizontal direction, and the absorption axis of the linear polarizer of the polarizing glasses is the front-side polarization The direction perpendicular to the absorption axis direction of the plate is preferable, and the absorption axis of the linear polarizer of the polarizing glasses is more preferably the vertical direction.
In addition, the absorption axis direction of the front-side polarizing plate of the liquid crystal display panel and the slow axis of the odd line retardation region and the even line retardation region of the patterning retardation film are 45 degrees on the efficiency of polarization conversion. It is preferable to make it.
In addition, about preferable arrangement | positioning of such polarized glasses, a patterning phase difference film, and a liquid crystal display device is disclosed by Unexamined-Japanese-Patent No. 2004-170693, for example.

  Examples of polarized glasses include those described in Japanese Patent Application Laid-Open No. 2004-170693, and examples of commercially available products include Zalman ZM-M220W accessories and LG 55LW5700 accessories.

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

1. Preparation of cellulose acylate film 101 (Preparation of cellulose ester solution 1-A)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution 1-A. The degree of acetyl substitution was measured according to ASTM D-817-91. The viscosity average degree of polymerization was measured by Uda et al.'S intrinsic viscosity method {Kazuo Uda, Hideo Saito, "Journal of Textile Society", Vol. 18, No. 1, 105-120 (1962)}.

―――――――――――――――――――――――――――――――――――
Composition of cellulose ester solution 1-A ――――――――――――――――――――――――――――――――――――
Cellulose ester (acetyl substitution degree 2.86, viscosity average polymerization degree 310)
100.0 parts by mass Plasticizer 1 (triphenyl phosphate) 8.0 parts by mass Plasticizer 2 (biphenyl diphenyl phosphate) 4.0 parts by mass UV absorber (UV-1 below) 0.8 part by weight UV absorber (UV-2 below) 0.2 parts by weight Methylene chloride 384 parts by weight Methanol 69 parts by weight Butanol 9 parts by weight ―――――――――――――――――――――――――― ―――――――――

(Preparation of matting agent dispersion 1-B)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent dispersion 1-B.

―――――――――――――――――――――――――――――――――――
Composition of Matting Agent Dispersion 1-B ―――――――――――――――――――――――――――――――――――
Silica particles having an average particle size of 16 nm (AEROSIL R972,
Nippon Aerosil Co., Ltd.) 10.0 parts by weight Methylene chloride 72.8 parts by weight Methanol 3.9 parts by weight Butanol 0.5 parts by weight Cellulose ester solution 1-A 10.3 parts by weight ―――――――― ―――――――――――――――――――――――――――

(Preparation of hindered amine compound solution 1-C)
The following composition was put into another mixing tank, stirred while heating to dissolve each component, and a hindered amine compound solution 1-C was prepared.

―――――――――――――――――――――――――――――――――――
Composition of hindered amine compound solution 1-C ――――――――――――――――――――――――――――――――――――
Hindered amine compounds (CHIMASSORB 2020FDL (manufactured by BASF))
20.0 parts by weight Methylene chloride 55.7 parts by weight Methanol 10 parts by weight Butanol 1.3 parts by weight Cellulose ester solution 1-A 12.9 parts by weight ――――――――――――――――― ――――――――――――――――――

(Production of cellulose ester film (101))
Add the matting agent dispersion 1-B to the cellulose ester solution 1-A, and further add the hindered amine compound solution 1-C so that HALS is 0.1 parts by mass, and stir well while heating. Was dissolved to prepare a dope. The obtained dope was heated to 30 ° C., and cast on a mirror surface stainless steel support, which was a drum having a diameter of 3 m, through a casting Giuser. The surface temperature of the support was set to −5 ° C., and the coating width was 1470 mm. The space temperature of the entire casting part was set to 15 ° C. The cellulose ester film cast and rotated 50 cm before the end point of the casting part was peeled off from the drum, and then both ends were clipped with a pin tenter. The residual solvent amount of the cellulose ester web immediately after stripping was 70%, and the film surface temperature of the cellulose ester web was 5 ° C.

  The cellulose ester web held by the pin tenter was conveyed to the drying zone. In the initial drying, a drying air of 45 ° C. was blown. Next, it was dried at 110 ° C. for 5 minutes and further at 140 ° C. for 10 minutes. In addition, the film was stretched at a widening ratio of 15% in the direction perpendicular to the transport direction. The film thickness of the produced cellulose ester film was 60 μm.

2. Formation of Hard Coat Layer A hard coat layer coating solution 1 having the composition described in the following table was prepared. After mixing each component, it filtered with the filter made from a polypropylene with the hole diameter of 30 micrometers, and prepared the coating liquid 1 for each hard-coat layer.

On the surface of the cellulose acylate film 101 produced above, the hard coat layer coating solution 1 was applied by a microgravure coating method under the condition of a conveyance speed of 30 m / min. After dried for 150 seconds at 60 ° C., with a nitrogen purge (hereinafter oxygen concentration of 0.5%), using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co.), illuminance 400 mW / cm ^2, irradiation The coating layer was cured by irradiating an ultraviolet ray with a quantity of 150 mJ / cm ² to form a hard coat layer (thickness 6 μm).
In this way, a hard coat layer was formed on the air side surface of each cellulose acylate film, and a cellulose acylate film with a hard coat layer was produced.

3. Production of optical film <Alkaline saponification>
Each of the prepared cellulose acylate films with a hard coat layer is passed through a dielectric heating roll at a temperature of 60 ° C., and after the film surface temperature is raised to 40 ° C., an alkaline solution having the composition shown below is applied to a bar coater. It was applied at a coating amount of 14 ml / m ² , heated to 110 ° C. and conveyed for 10 seconds. Subsequently, 3 ml / m ^{2 of} pure water was applied using the same bar coater. Subsequently, washing with water and draining with an air knife were repeated three times, followed by transporting to a drying zone at 70 ° C. for 10 seconds and drying to prepare an alkali saponified cellulose acylate transparent support with a hard coat layer.

────────────────────────────────────
Composition of alkaline solution (parts by mass)
────────────────────────────────────
Potassium hydroxide 4.7 parts by weight Water 15.8 parts by weight Isopropanol 63.7 parts by weight Surfactant SF-1: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H 1.0 part by weight Propylene glycol 14. 8 parts by mass ────────────────────────────────────

<Preparation of transparent support with rubbing alignment film>
A rubbing alignment film coating solution having the following composition was continuously applied with a # 8 wire bar to the saponified surface of the prepared support. The alignment film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds. Next, a stripe mask having a lateral stripe width of 364 μm at the transmission portion and a lateral stripe width of 364 μm at the shielding portion is disposed on the rubbing alignment film, and a metal halide having an illuminance of 2.5 mW / cm ² in the UV-C region under room temperature air. The alignment layer for the first retardation region was formed by irradiating ultraviolet rays for 4 seconds using a lamp to decompose the photoacid generator and generate an acidic compound. Thereafter, a rubbing treatment was performed once in one direction at 500 rpm while maintaining an angle of 45 ° with respect to the stripe of the stripe mask, and a transparent support with a rubbing alignment film was produced. The thickness of the alignment film was 0.5 μm.
────────────────────────────────────
Composition of coating solution for alignment film formation ────────────────────────────────────
3.9 parts by mass of polymer material for alignment film (PVA103, Kuraray Co., Ltd. polyvinyl alcohol)
Photoacid generator (S-2) 0.1 parts by weight Methanol 36 parts by weight Water 60 parts by weight ──────────────────────────── ────────

<Preparation of patterned optically anisotropic layer>
The following coating liquid for optically anisotropic layer was applied at a coating amount of 4 ml / m ² using a bar coater. Next, after aging at a film surface temperature of 110 ° C. for 2 minutes, the film is cooled to 80 ° C. and irradiated with ultraviolet rays for 20 seconds using a 20 mW / cm ² UV metal halide lamp in the air to fix the alignment state. Thus, a patterned optical anisotropic layer was formed, and an optical film 101 (Example 101) was produced. In the mask exposure portion (first retardation region), the discotic liquid crystal is vertically aligned with the slow axis direction parallel to the rubbing direction, and the unexposed portion (second retardation region) is orthogonally aligned perpendicularly. It was. The film thickness of the optically anisotropic layer was 0.9 μm.

────────────────────────────────────
Composition of coating solution for optically anisotropic layer ────────────────────────────────────
Discotic liquid crystal E-1 100 parts by mass alignment film interface alignment agent (II-1) 3.0 parts by mass air interface alignment agent (P-1) 0.4 parts by mass photopolymerization initiator 3.0 parts by mass (Irgacure 907 , Manufactured by Ciba Specialty Chemicals Co., Ltd.)
Sensitizer (Kayacure-DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 part by weight Methyl ethyl ketone 400 parts by weight ───────────────────────── ───────────

4). Preparation of cellulose acylate film 301 <Preparation of cellulose acylate>
A cellulose acylate having an acetyl substitution degree of 2.87 was prepared. This was carried out by adding sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) as a catalyst, adding carboxylic acid as a raw material for the acyl substituent, and carrying out an acylation reaction at 40 ° C. In addition, aging was performed at 40 ° C. after acylation. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.

<Preparation of dope 301 liquid for support side skin layer>
(Preparation of cellulose acylate solution 2-A)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution 2-A.
―――――――――――――――――――――――――――――――――――
Composition of cellulose acylate solution 2-A ――――――――――――――――――――――――――――――――――――
Cellulose ester (acetyl substitution degree 2.86, viscosity average polymerization degree 310)
100.0 parts by mass Plasticizer 1 (triphenyl phosphate) 8.0 parts by mass Plasticizer 2 (biphenyl diphenyl phosphate) 4.0 parts by mass Methylene chloride 353.9 parts by mass Methanol 89.6 parts by mass Butanol 4.5 Mass part ――――――――――――――――――――――――――――――――――――

(Preparation of matting agent solution 2-B)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent solution 2-B.
―――――――――――――――――――――――――――――――――――
Composition of matting agent solution 2-B ――――――――――――――――――――――――――――――――――――
Silica particles having an average particle size of 20 nm (AEROSIL R972,
Nippon Aerosil Co., Ltd.) 2.0 parts by weight Methylene chloride 69.3 parts by weight Methanol 17.5 parts by weight Butanol 0.9 parts by weight The cellulose acylate solution 2-A 0.9 parts by weight ―――――――――――――――――――――――――――――

(Preparation of hindered amine compound solution 2-C)
The following composition was put into a mixing tank, stirred while heating to dissolve each component, and a hindered amine compound solution 2-C was prepared.

―――――――――――――――――――――――――――――――――――
Composition of hindered amine compound solution 2-C ――――――――――――――――――――――――――――――――――――
Hindered amine compounds (CHIMASSORB 2020FDL (manufactured by BASF))
10.0 parts by weight Methylene chloride 61.0 parts by weight Methanol 15.4 parts by weight Butanol 0.8 parts by weight The cellulose acylate solution 2-A 12.8 parts by weight ――――――――――――― ――――――――――――――――――――――

  1.3 parts by mass of the matting agent solution 2 and 0.88 parts by mass of the hindered amine compound solution 3 were mixed using an in-line mixer after filtration, and 97.8 parts by mass of the cellulose acylate solution 1 was further added. Then, the mixture was mixed using an in-line mixer to prepare a support-side skin layer solution 101.

<Preparation of core layer dope 301>
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a core layer dope 301.
―――――――――――――――――――――――――――――――――――
Composition of core layer dope 301----------------------
Cellulose ester (acetyl substitution degree 2.86, viscosity average polymerization degree 310)
100.0 parts by mass Plasticizer 1 (triphenyl phosphate) 8.0 parts by mass Plasticizer 2 (biphenyl diphenyl phosphate) 4.0 parts by mass Ultraviolet absorber (UV-1) 1.6 parts by mass Ultraviolet absorber (UV-2 above) 0.4 parts by weight Methylene chloride 297.7 parts by weight Methanol 75.4 parts by weight Butanol 3.8 parts by weight ――――――――――――――――――― ―――――――――――――――

<Preparation of dope 301 liquid for air side skin layer>
For the air side skin layer, 1.3 parts by mass of the matting agent solution 2 and 99.3 parts by mass of the cellulose acylate solution 1 prepared in the dope 301 solution for the support side skin layer were mixed using an in-line mixer. Solution 301 was prepared.

<Casting>
Using a drum casting apparatus, the prepared base layer dope (core layer dope) and the surface layer dope (air side skin layer dope and support side skin layer dope) on both sides are made of stainless steel simultaneously. The film was uniformly cast from a casting port on a casting support (support temperature −9 ° C.). Stripped in a state where the amount of residual solvent in the dope of each layer is about 70% by mass, fixed both ends in the width direction of the film with a pin tenter, and 1.28 in the lateral direction in a state of residual solvent amount of 3-5% by mass. The film was dried while being stretched twice. Then, it further dried by conveying between the rolls of a heat processing apparatus, and the cellulose acylate film of Example 301 was obtained. The obtained cellulose acylate film had a thickness of 60 μm (air-side skin layer 3 μm, core layer 54 μm, support-side skin layer 3 μm), and a width of 1480 mm.

The same as the cellulose acylate film 101 except that the coating liquid 1 for hard coat layer was applied on the air side surface of the produced cellulose acylate film 301 by the microgravure coating method under the condition of a conveyance speed of 30 m / min. Thus, a cellulose acylate film with a hard coat layer was produced.
Further, a patterned optical anisotropic layer was formed by the same method as that for the cellulose acylate film 101 to produce an optical film 301.

<Preparation of optical films 102-118, 201>
As described in Table 2 below, the optical films 102 to 118 (the optical films 102 to 118 (not shown) were prepared in the same manner as the optical film 101 except that the amount of hindered amine compound added, the hard coat layer coating solution, etc. Examples 102 to 118) and an optical film 201 (Comparative Example 201) were produced.

<Preparation of optical films 302 to 320, 401>
As described in Table 3 below, the optical films 302 to 320 (Examples 302 to 320), except that the amount of hindered amine compound added was changed and the draw ratio was changed, in the same manner as the production of the optical film 301. And the optical film 401 (comparative example 401) was produced.

5. Evaluation (measurement of sound velocity in TD direction (direction perpendicular to transport direction))
The speed of sound (acoustic wave propagation speed) of the cellulose acylate film is measured using an orientation measuring machine (SST-2500: manufactured by Nomura Corporation) after conditioning the film for 2 hours at 25 ° C. and 60% relative humidity. did. The value when the measuring device was installed in parallel with the winding direction of the roll of film was the longitudinal sound velocity (MD sound velocity), and the value when the measuring device was installed in the direction orthogonal to the winding direction was defined as the transverse sound velocity (TD sound velocity).

(Measurement of Re and Rth)
Re and Rth for light having a wavelength of 550 nm were measured by KOBRA 21ADH (manufactured by Oji Scientific Instruments).

(Humidity dimensional change rate)
The humidity dimensional change rate of the cellulose acylate film was measured by the following method.
Let the winding direction of a film roll be a longitudinal direction (MD direction) and the width direction (TD direction) orthogonal to a longitudinal direction. A film sample having a length of 12 cm in the measurement direction and a width of 3 cm was cut out with the longitudinal direction or the width direction as the measurement direction. Pin holes were made in the sample at intervals of 10 cm along the measurement direction, the humidity was adjusted for 24 hours at 25 ° C. and 10% relative humidity, and the distance between the pin holes was measured with a pin gauge (measured value is L ₀ ). ). Next, the sample was conditioned at 25 ° C. and 80% relative humidity for 24 hours, and the distance between the pin holes was measured with a pin gauge (measured value is L ₁ ). Using these measured values, the humidity dimensional change rate was calculated by the following formula.
Humidity dimensional change rate [%] = (L ₁ −L ₀ ) * 100 / L ₀

(Evaluation of light adhesion)
First, the optical films of each of the Examples and Comparative Examples prepared above were irradiated with light for 100 hours in an environment of 60 ° C. and 50% relative humidity with Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd. did.
Next, each of the optical films was conditioned for 2 hours under the conditions of a temperature of 25 ° C. and a relative humidity of 60%. The surface on the side having the hard coat layer is cut into 11 grids in a grid pattern with a cutter knife, and a total of 100 square grids are carved, and the surface is made by Nitto Denko Corporation. A polyester adhesive tape (No. 31B) was attached. After 30 minutes, the tape was quickly peeled off in the vertical direction, and the number of squares peeled off was counted and evaluated according to the following four criteria. The same adhesion evaluation was performed 3 times and the average was taken. The results are shown in the table below.
No peeling was observed at 5: 100 mm.
4: Peeling of 1 to 2 mm was observed at 100 mm.
3: Peeling of 3 to 10 mm was observed at 100 mm (within an allowable range).
2: Peeling of 11 to 20 mm was observed at 100 mm.
Peeling of 21 mm or more was observed at 1: 100 mm.

(Crosstalk evaluation)
The 32ZP2 FPR film made by Toshiba was peeled off, and each of the produced optical films was bonded instead.
After the 3D monitor produced above is lit continuously for 48 hours, the right eye pixel is displayed in white and the left eye pixel is displayed in black. A spectral radiance meter (SR-3 Topcon) is placed at the eye position. The luminance was measured through each of circular polarizing glasses for the left eye.
The luminance when passing through the right-eye circular polarizing glasses is Y_RR, and the luminance when passing through the left-eye circular polarizing glasses is Y_RL.
Since the 3D feeling is lost when the right eye image enters the left eye and the left eye image enters the right eye, the degree of crosstalk is defined as CRO = (YRR−YRL) / (YRR + YRL) and evaluated. The CRO immediately after lighting was set to CRO_0, and the CRO after lighting for 48 hours was set to CRO_48. The display performance at the time of continuous lighting was evaluated based on the value of 100 * CRO_48 / CRO_0 according to the following criteria.
5: 95% or more 4: Less than 95% to 92.5%
3: Less than 92.5% to 90% or more (within tolerance)
2: Less than 90% to 80% or more and less than 1: 80% As an allowable evaluation value, “5” is most preferable, “4” is next preferable, and “3” is next preferable. “2” is an evaluation value that needs improvement and is not allowed.

  From the table, the example using the support containing 0.001% by mass or more of the hindered amine compound in cellulose acylate shows that the adhesion between the functional layer such as the hard coat layer and the support is improved. Recognize. Moreover, since the dimensional change of a support body is suppressed, when the optical film of this Example is used, it turns out that crosstalk is reduced.

DESCRIPTION OF SYMBOLS 1 Dope for skin layers 2 Dope for core layers 3 Co-casting Giesa 4 Casting support 12 Pattern optical anisotropic layer 12a First retardation region 12b Second retardation region 14 Support film 16 Functional layer

Claims (2)

Stretching a film containing at least cellulose acylate and a hindered amine compound;
Disposing a functional layer on the film;
Arranging a pattern optical anisotropic layer on the surface of the film opposite to the surface on which the functional layer is disposed, in this order,
The method for producing an optical film, wherein the hindered amine compound is contained in an amount of 0.001% by mass or more based on the cellulose acylate. The step of disposing the patterned optically anisotropic layer on the film includes disposing the patterned optically anisotropic layer via an alignment film, and the one of the alignment film and the patterned optically anisotropic layer. the method for producing an optical film according to claim 1 comprising the step of performing UV irradiation.

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